Html markup on your pages is probably minuscule after compression (you're using zopfli with 5000 cycles and minifying your html, right?), and amortizing the upfront cost of that extra js over the average number of page views is definitely worse than plain ol static html for your blog 99.9% of the time.
But let's get real; theoretically the best? I doubt markdown is even near the optimum in terms of bits on the wire. Don't even talk to me unless you're writing your own binary markdown serialization format.
Html markup on your pages is probably minuscule after compression (you're using zopfli with 5000 cycles and minifying your html, right?), and amortizing the upfront cost of that extra js over the average number of page views is definitely worse than plain ol static html for your blog 99.9% of the time.
But let's get real; theoretically the best? I doubt markdown is even near the optimum in terms of bits on the wire. Don't even talk to me unless you're writing your own binary markdown serialization format.